code: def test_alpha():
      image = np.random.uniform(size=(3, 3))
      label = np.random.randint(0, 9, size=(3, 3))
      # If we set `alpha = 0`, then rgb should match image exactly.
      rgb = label2rgb(
          label, image=image, alpha=0, image_alpha=1, bg_label=-1
      )
      assert_array_almost_equal(rgb[..., 0], image)
      assert_array_almost_equal(rgb[..., 1], image)
      assert_array_almost_equal(rgb[..., 2], image)
  
imports: import itertools
  import numpy
  import pytest
  from numpy.testing import assert_array_almost_equal, assert_array_equal, assert_no_warnings, assert_warns
  from skimage._shared.testing import expected_warnings
  from skimage.color.colorconv import hsv2rgb, rgb2hsv
  from skimage.color.colorlabel import label2rgb
label_desc: Use image node_id 5 for calling a global function with example usage: test_alpha() without return types